Purpose:
Neovascular age-related macular degeneration (AMD) affects millions of Americans and is a leading cause of vision loss. Therapy with anti-VEGF agents is now the gold standard of therapy. Clinicians have identified that certain patients appear to improve with these treatments, while others remain stable or worsen during treatment. This study aims to identify and quantify subgroups of patients’ response to anti-VEGF treatment.

Methods:
The study design is a retrospective review of the electronic charts of all patients of 3 academic physicians in a large urban referral center. All methods were approved by our institution’s IRB. Inclusion criteria were set as all encounters of patients who visited the 3 physician investigators between July 15, 2010 and July 15, 2014. The dataset was restricted to complete records with the ICD9 diagnosis code 362.52 for neovascular AMD and CPT code 67028 for intravitreal injection.

Results:
Over the 4 year period studied, 405 eyes (324 unique patients) were treated with 4939 intravitreal injections with bevacizumab, ranibizumab or aflibercept by the 3 investigators. Of these patients, 74 eyes (58 unique patients) received only one injection. The other 331 eyes received an average of 14.7 ± 12.5 injections (mean ± SD). Of the 331 eyes, 24 (7%) presented with a VA of CF or worse. 16 (66%) of these eyes remained CF, and only 1 eye improved to a Snellen VA better than 20/200. In addition, 16 eyes (5%) presented with VA better than CF but deteriorated to CF or worse over the course of treatment.<br /> Of the 291 eyes with numeric Snellen VA data, the average initial VA was 0.46 logMAR (20/58 Snellen) and average final VA was 0.44 logMAR (20/56 Snellen). 170 eyes (58%) maintained a VA within 2 lines, while 56 eyes (19%) lost more than 2 lines of VA and 66 (23%) gained more than 2 lines. Of the eyes which gained more than 2 lines, 16 (24%) received less than 5 injections, while 17 (26%) received more than 20 injections. Of the eyes which lost more than 2 lines, 21 (38%) received more than 20 injections.

Conclusions:
There is a wide distribution of response to anti-VEGF treatment in neovascular AMD, which poses a significant challenge to physicians planning treatment. Future studies can be directed at determining which factors may be associated with a favorable or poor response to particular anti-VEGF agents.